XML 25 R1.htm IDEA: XBRL DOCUMENT v3.25.3
Document And Entity Information - USD ($)
 12 Months Ended
Sep. 30, 2025
Nov. 30, 2025
Mar. 31, 2025
Document Information [Line Items]      
Entity Central Index Key 0001069533    
Entity Registrant Name RGC Resources, Inc.    
Amendment Flag false    
Current Fiscal Year End Date --09-30    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2025    
Document Type 10-K    
Document Annual Report true    
Document Period End Date Sep. 30, 2025    
Document Transition Report false    
Entity File Number 000-26591    
Entity Incorporation, State or Country Code VA    
Entity Tax Identification Number 54-1909697    
Entity Address, Address Line One 519 Kimball Ave., N.E.    
Entity Address, City or Town Roanoke    
Entity Address, State or Province VA    
Entity Address, Postal Zip Code 24016    
City Area Code 540    
Local Phone Number 777-4427    
Title of 12(b) Security Common Stock, $5 Par Value    
Trading Symbol RGCO    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 171,906,919
Entity Common Stock, Shares Outstanding   10,350,531  
Auditor Firm ID 34    
Auditor Name Deloitte & Touche LLP    
Auditor Location Richmond, Virginia